Applied, and while I was at it, also changed the link text from "here" to "libstdc++ manual".
Gerald Index: gcc-4.3/porting_to.html =================================================================== RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.3/porting_to.html,v retrieving revision 1.13 diff -u -r1.13 porting_to.html --- gcc-4.3/porting_to.html 14 Nov 2015 20:53:58 -0000 1.13 +++ gcc-4.3/porting_to.html 25 Feb 2017 15:36:44 -0000 @@ -314,7 +314,9 @@ </tr> </table> -<p>For future reference, available headers are listed <a href="https://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt01ch03s02.html">here</a>. +<p>For future reference, available headers are listed in the <a +href="https://gcc.gnu.org/onlinedocs/libstdc++/manual/using_headers.html">libstdc++ +manual</a>. </p> <p>An example.</p>